Oxyacetic acid compounds as builders for detergent compositions

ABSTRACT

A PHOSPHATE-FREE BIODEGRADABLE DETERGENT BUILDER COMPATIBLE WITH VARIOUS SYNTHETIC DETERGENT AND SOAP FORMULATIONS TO PRODUCE GENERALLY NON-EUTROPHIC DETERGENT PRODUCTS. THE BUILDER IS A WATER-SOLUBLE SALT OF AN ALIPHATIC OXYHYDROCARBON CARBOXYLIC COMPOUND HAVING CARBOXYLIC RADICALS SEPARATED FROM INTERNAL OXYGEN ATOMS BY AT LEAST ONE UNSUBSTITUTED HYDROCARBON RADICAL. A PREFERRED BUILDER IS AN ALKYL METAL SALT OF TRIGLYCOLIC ACID AND THE BUILDERS OF THE INVENTION ARE COMBINABLE IN WEIGHT RATIOS WITH THE DETERGENT ACTIVE SURFACTANTS IN THE FORMULATIONS RANGING FROM ABOUT 20:1 TO ABOUT 1:10.

United States Patent 3,725,290 OXYACETIC ACID COMPOUNDS AS BUILDERS FORDETERGENT COMPOSITIONS Douglas Carlyle Nelson, Glenview, and EdwardAndrew Knaggs, Deerfield, Ill., assignors to Stepan Chemical Company,Northfield, Ill.

No Drawing. Continuation-impart of abandoned application Ser. No.98,887, Dec. 16, 1970. This application May 12, 1972, Ser. No. 252,718

Int. Cl. Clld 3/20; C07c 55/22, 55/24 US. Cl. 252-410 12 Claims ABSTRACTOF THE DISCLOSURE A phosphate-free biodegradable detergent buildercompatible with various synthetic detergent and soap formulations toproduce generally non-eutrophic detergent products. The builder is awater-soluble salt of an aliphatic oxyhydrocarbon carboxylic compoundhaving carboxylic radicals separated from internal oxygen atoms by atleast one unsubstituted hydrocarbon radical. A preferred builder is analkyl metal salt of triglycolic acid and the builders of the inventionare combinable in weight ratios with the detergent active surfactants inthe formulations rang ing from about :1 to about 1:10.

CROSS-REFERENCE TO RELATED APPLICATION This is a continuation-in-part ofour copending US. Ser. No. 98,887, filed Dec. 16, 1970, now abandoned.

BACKGROUND OF THE INVENTION Field of the invention The invention relatesto organic builders for detergent compositions and more particularly tobiodegradable nonor low-eutrophic builders compatible with variousorganic anionic, nonionic and/or amphoteric surface active compoundswhich are functional as detergents or cleaners.

Prior art The use of builders in detergent compositions is well known.Builders are generally considered to be required in detergentformulations to improve detergency levels of the detergent compositions.Due to the complex nature of detergency, i.e., the various and numerousphysicochemical and other factors involved, there has been no generalbasis found with respect to the functional characteristics or thechemical structure of the compounds from which the behavior of adetergent builder could be predicted. In general, detergent builders arebelieved to affect to various degrees such fatcors in detergent systemsas stabilization and/or anti-redeposition of soil suspensions,emulsification of soil particles, surface activity of j the aqueousdetergent solutions, solubilization of water insoluble materials, foamor suds producing character- 1 sarily render its use advantageous indetergent composi ice tions. A detergent builder should, among otherthings, be compatible not only with various available detergentmaterials but also with the various additives conventionally utilized,be hydrolytically stable in hot or cold alkaline aqueous solutions, becompatible with various bleaching and the like agents and, of course,not corrode and otherwise adversely afiect the fabrics being washed orthe equipment utilized for such washing operations.

Additionally, a builder should be biodegradable and be generallynon-eutrophic (that is, contain a minimum or no elements which cannot beconverted into carbon dioxide and water) in various waste watertreatment systems, whether man-made or natural. Heretofore, knownbuilders which have found some acceptability include various phosphorousand nitrogen containing compounds, such as for example, sodiumtripolyphosphate (STPP) or salts of nitrilotriacetic acid (NTA). Whilesome controversy may exist as to major causes of eutrophication ofvarious bodies of water, in most instances it. is generally recognizedthat phosphorous and nitrogen are most suspect as being the controllingfactor; even though carbon has been shown to also contribute toeutrophication. Interested governmental bodies have concluded thatphosphorous, and to a certain extent nitrogen, sources ofnutrients mustbe controlled if eutrophication is to be successfully attacked.Accordingly, the term non-eutrophic as used herein shall mean materialsfree from phosphorous and/or nitrogen sources of nutrients. Thus,presently acceptable nitrogen and/or phosphorous containing builders aresuspect of contributing to water pollution by providing eutrophicationconditions in bodies of water which are conducive to algae and otheraquatic plants as well as bacterial growth, eventually rendering suchbodies of water unfit for aquatic life or any other use. Phosphorousfertilizes excessive growth of algae and other aquatic weeds. As theseplants die and decay they use up the oxygen in the water, cause fish tosuffocate, and much of their phosphorous content is redissolved tofertilize yet another cycle or excessive plant growth. Finally, theaccumulated masses of decayed vegetation fill the lake and turn it intoa noisome bog. Nitrogen based organic builders are also said tocontribute a similar fertilizer action, and ideally should be avoided.

Other builder materials are also known, as exemplified by German DisplayPat. No. 1,926,422 or by Canadian Pat. No. 853,647 which do not possessthe above disadvantage, nevertheless have other disadvantages, either ofan economical or a functional nature. To one degree .or another, allknown builders, organic or inorganic, have certain limitations anddisadvantages, such as those previously pointed out, and improvedbuilders are continuously sought which would obviate or at leastminimize the limitations and disadvantages of the prior art detergentbuilders.

SUMMARY OF THE INVENTION The invention provides in its preferredembodiments a nitrogen and phosphorous-free biodegradable substantiallynon-toxic organic builder compatible with awide range of detergent andsoap formulations for the production of non-eutrophic detergent andcleanser products.

The builders of the invention generally are water-soluble salts ofaliphatic oxy-hydrocar-bon carboxylic compounds having carboxylicradicals separated from internal oxygen atoms by at least oneunsubstituted hydrocrbon radical (i.e. an alkylene radical). Of thesecompounds, a preferred embodiment is the alkali metal, NH, and aminesalts of the oxyacetic acid group and a specific preferred builder isneutralized triglycolic acid. The builders of the invention arecompatible in liquid or dry detergent 'and cleanser formulations in wideweight ratios ranging from about 100:1 to about 1:100.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The detergent builders of theinvention can be produced by many different organic synthesis methodsincluding the oxidation of polyethylene glycols, ethoxylated glycerines,and ethoxylated polyols and generally comprise carboxyl ether compoundshaving spatial or steric characeristics for sequestering and/orchelating various metal ions, particularly the Ca and the Mg ions. Suchproducts are utilized as their alkali metal, NH, and amine salts andpreferably are utilized as the alkali metal salts. Somewhat morespecifically, the detergent builders of the invention are salts ofaliphatic oxyhydrocarbon carboxylic compounds having carboxylic radicalsseparated from internal oxygen atoms by at least one unsubstitutedhydrocarbon radical and the preferred embodiments are represented by theformula:

wherein (CH is termed the unsubstituted hydrocarbon radical andpreferably n and x are whole integers ranging from 1 to 5, M is selectedfrom the group consisting essentially of alkali metals, ammonium andamines, and R is selected from the group consisting essentially of:

V wherein y is an integer ranging from 0 to 5.

A number of such aliphatic oxy-hydrocarbon carboxylic compounds areoxyacetic acids which exhibit good Ca/Mg chelating properties anddetergent building characteristics and include the acids per se and thealkali metal, NH, and amine salts of the following:

Diglycolic acid (i.e. oxy-diacetic acid) Triglycolic acid (i.e. 1,2-bis(cazboxy methoxy) ethane) Tetraglycolic acid (i.e. 1,2-bis (carboxymethoxy) ethyl ether) Tris (carboxy methoxy ethoxy) propane Symmetricaltetra(carboxy methoxy) neo-pentane the above enumerated acids and saltsof the aliphatic oxyhydrocarbon carboxylic compounds, such as a mixtureof neutralized or unneutralized diglycolic, triglycolic, tetraglycolic,tris(carboxy methoxy ethoxy) propane and/or tetra(carboxymethoxy)neo-pentane that is attained by certain synthesis route.

The builders of the present invention are not only effective andeconomical detergent builders but also exhibit many and variousadvantageous properties, which include hydrolytical stability, i.e.,resistance to decomposition or degradation at elevated temperatureand/or pH conditions, relative inertness toward various fabrics andequipment associated with laundering operations, low-toxic or irritatingcharacteristics toward humans, compatibility with detergents, soaps,bleaching agents, additives and other various agents customarily indetergent formulations. Additionally, the builders of the invention are=biodegradable and generally non-eutrophic, being nitrogen andphosphorous free (or at least having a low proportion thereof) andsusceptible to bacteria attack without providing sutiicient nutrientsfor the excessive growth and/or reproduction af algae, aquatic plantlife, bacterial growth, and the like.

As mentioned, the builders of the invention are utilizable with any ofthe conventional detergent classes and mixtures thereof, as syntheticnonsoaps, soaps, anionic, nonionic and/or amphoteric surface activecompounds suitable as cleaning agents. These compounds include sulfatedor sulfonated alkyl, aryl and alkyl-aryl hydrocarbons and alkali metalsalts thereof, for example, sodium salts of long chain alkyl sulfonates,sodium salts of alkyl benzene sulfonates, such as C to C alkyl-benzolsulfonates, etc. Examples of other detergent materials are shown inpertinent literature sources, such as the book by Schwartz, Perry andBerch entitled Surface Active Agents and Detergents; Inter SciencePublishers, New York (1949), which is incorporated herein by reference.

The amount of builder of the invention necessary for effective use witha surface active compound or formulation thereof (i.e., active) variesover a wide range and is regulated by a number of factors including theintended end use, the type of active surfactant employed, pH conditions,water hardness, etc. In general, the builders of the invention can beemployed in detergent compositions in any desired proportion and includeweight ratios of builder to active detergent material that range fromabout 20:1 to about 1:10 and in certain embodiments range from about 5:1to 1:1.

The builders of the invention are utilizable per se and are oftenadvantageously utilized to replace a portion or all of other builderspresently employed in detergent formulations. While for eutrophicationreasons and otherwise it is desirable to exclusively use the detergentbuilders of the invention, they nevertheless can be incorporated intodetergent formulations in combination with other builders such as sodiumtripolyphosphate (STPP), nitrilotriacetic acid salts (NTA) and/orpolyelectrolyte builders. For example, conventional alkali metalpolyphosphates, such as tetrasodium polyphosphate, etc., or similaralkali metal and ammonium salts of nitrilotriacetic acid are readilycompatible with the builders of the invention in particular detergentformulations. Generally, the weight ratio of the aliphaticoxyhydrocarbon carboxylic builders to such known builders or buildermixtures ranges from about 1:10 to about 10:1.

The builders of the invention are formulated into detergent compositionsin any form whatsoever including liquids, powders, flakes, beads,tablets, pellets, pastes, suspensions, aerosols, etc. and utilized in aconventional manner. The manner of formulation is not determinative ofthe invention and is selected as desired in accordance with theformulation being produced. The builders of the invention are obtainablefrom a number of known processes and as illustrative thereof, thefollowing are mentioned: air oxidation of diethylene glycol; air-nitricacid catalytic oxidation of diethylene glycol; reaction of formaldehydewith carbon monoxide and water, reaction of chloroacetic acid with abase, etc.

In order to illustrate, but in no way limit the invention, exemplarysynthesis routes for certain of the builders of the invention are setforth:

DEMONSTRATION A Oxidation of triethylene glycol A solution of nitricacid comprised of 6 mols (540 grams) of 70% nitric acid in 90 grams ofwater was prepared and then 0.6 gram of ammonium vanadate was added. Thesolution was heated to about 68 C. and stirred continuously whileapproximately 1 gram of triethylene glycol was added. After severalminutes, brown fumes started to evolve indicating the initiation ofoxidation. Then 1 mol (150 grams) of triethylene glycol was slowly addedto the turning solution over a 70 minute period while maintaining themoderately exothermic reaction at about 67 to 73 C. with continuedstirring. After all of the triethylene glycol was added, the reactionmixture was allowed to stand for about 2 hours at about 65 C. tocomplete the reaction. A clear blue solution resulted, which wasconcentrated and dried under vacuum and heat to yield about 181.1 gramsof a brown solid.

The crude brown solid product was dissolved in water (approximately a50% solution) and the solution was adjusted to a pH with a sodiumhydroxide solution (50%). The solution was then concentrated to aviscous liquid and mixed with a large amount of ethyl alcohol toprecipitate a white solid product. After the precipitate wasfilteredfrom the solution and dried, it was analyzed as the disodium salt oftriglycolic acid, the calcium chelation value of this salt being 197me./ g.

A substantially similar run was made without the use of the vanadatecatalyst. The reaction was initiated with brown fumes from anothernitric acid oxidation reaction. The reaction yields a crude producthaving a calcium chelation value of 174.8.

DEMONSTRATION B Oxidation of tetraethylene glycol A solution of 1080grams of 70% nitric acid in 180 grams of water was prepared. 1.29 gramsof ammonium vanadate was added to the solution and it was heated toabout 68 C., with continuous stirring and a small amount (about 1 gram)of tetraethylene glycol (available from Union Carbide) added. Theoxidation reaction started almost immediately. 388.4 grams oftetraethylene glycol was slowly added with continuous stirring in asimilar manner as described in Demonstration A. The crude product wasneutralized with sodium hydroxide to yield a salt analyzed as disodiumtetraglycolic acid. The calcium chelation value of this salt was 78.6but the acid form exhibited ahigher chelation value.

DEMONSTRATION C Oxidation of ethoxylated pentaerythritol Pentaerythritol(680 grams, 5 mols) was reacted with ethylene oxide (approximately 20mols) using potassium hydroxide (3.4 grams) as a catalyst in a 1 gallonautoclave. The reaction temperature was maintained at about 190 C. orless and a pressure of 70 p.s.i. or less.

The ethoxylated pentaerythritol (312 grams) was then oxidized withnitric acid (1080 grams of 70% acid) and ammonium vanadate (0.8 gram) atabout 70 C. over a period of about 3 hours. The dried product (318grams) exhibited an acid value of 8.90 me./g., with the theoreticalvalue for C[CH OCH COOH] being 10.8. Thecalcium chelation value for thisacid product was 171 mg./ g.

The acid product was neutralized with sodium hydroxide to a pH 10 anddried to yield the sodium salt thereof, which had a chelation value of138 mg./g.

DEMONSTRATION D Ethoxylation of ethylene glycol Potassium hydroxide (2grams) was dissolved in ethylene glycol (1240 grams) and charged to aone-gallon autoclave. The autoclave Was purged with nitrogen and heatedto C. Ethylene oxide was slowly pumped into the autoclave while thereaction temperature was maintained at about to C. and pressure variedfrom 0 to 50 p.s.i. At intervals the ethylene oxide addition was stoppeduntil all of it that had been added was reacted, as indicated by thedecrease of pressure in the autoclave. Periodic samples were removed andanalyzed for the number of mols of ethylene oxide added to ethyleneglycol. A mixture of homologues was noted with increased additions ofethylene oxide over the reaction time.

The mixed homologues were then oxidized with nitric acid substantiallyas set forth in the preceding demonstration to yield a mixed oxidatecontaining the various builders of the invention including diglycolictriglycolic, tetraglycolic, tris (carboxy-methoxy-ethoxy) propane andtetra (carboxy-methoxy) neo-pentane. Such mixture is useful as a buildermaterial and the above synthesized route provides a commercial feasiblecontinuous system of producing the same.

COMPARATIVE CHELATION VALUES Tetraglycolic (Na) Tris (carboxy methoxyethoxy) propane (Na) Tetra (carboxy methoxy) neopentane (Na) 138 (117 asacid).

87 (104 as acid).

95 (110 as acid).

In order to illustrate but in no way limit the invention and compare itwith known builders and detergent formulations, a builder of theinvention, i.e., disodium diglycolic acid (DSDGA), was formulated intodetergent compositions and compared against substantially identicaldetergent compositions utilizing known builders, i.e., sodiumtripolyphosphate (STPP) and sodium nitrilotriacetic acid (NTA), and wasstudied for building characteristics under laundry operational.conditions. The aqueous study solutions had a hardness of 180 p.p.m., atotal detergent concentration of about 0.15% (solids), a temperature of120 F. and a pH of about 9. A standardized Terg-o-Tometer laboratorymachine washing procedure was utilized on standard soiled fabricspecimens.

The following exemplary embodiment of an ionic detergent composition wasused in this study, as set forth below, with the percentages being byweight.

Percent Linear sodium alkyl (C -C benzol sulfonate (NaLAS) 18 Alkalimetal carboxy methyl cellulose (CMC) 0.5 Builder (STPP; 'NTA; DSDGA)30-50 Sodium silicate 5 Sodium sulfate (Na- 50 Q.S.

1 Quantity sufilclent.

Sodium silicate is available in various combinatons of S0 and Na O, witheach particular combination having, for example, individual toxicitycharacteristics. A selected sodium silicate may require proper pHadjustment in view of the end use of the detergent composition utilizingthe same.

TABLE I.-DETERGENOY TESTS Detergency Builder units 1 STPP, 20% STPP,30%.. STPP, 40% S'IPP (NTA) N as, 40?, (NTA) Na 50% DSD GA, 20% DSD GA,30%.

(a SKD GA; 20%

SKD GA, 30%. SKD GA, 40%.

SKD GA, 50%- DAD GA; 20 z, DAD GA, 309.- DAD GA, 40 DAD GA, 60-

DTD GA," 20% DTDGA, 30%--. DTD GA, 40% DTD GA, 50%

1 Detergency units: D. U.=R i-R Where Rdr=reflectance units afterwashing, and

Rdi=refiectance units before washing. 9 DKD GA: dipotassium salt ofdiglycolic acid. 8 SKD GA: monosodium-monopotassium salt of diglycollcacid 4 DAD GA: dlammonium salt of diglycolic acid. b DTD GA:ditriethanolamine salt of diglycolic acid.

the above results demonstrate that certain embodiments of the buildersof the invention have advantageous characteristics at lower builderlevels over at least some of the known builders. It should be noted thatdespite their relatively favorable detergency characteristics, thediglycolic builder compounds are not the preferred embodiment of thebuilder compounds of the invention because of their relativelyunfavorable toxicity characteristics.

To further illustrate the ability of the builders of the invention andcompare them with known builders, additional detergent formulations wereproduced, which were identical to each other except for the builderutilized. The hardness of the aqueous solutions under consideration werevaried between 350 p.p.m. and 140 p.p.m., the solutions had a totaldetergent concentration of about 0.2%, a temperature of 120 F. and wereutilized on standard soiled fabric specimens in a standardizedTergo-Tometer washing procedure.

An exemplary embodiment of an ionic detergent composition was utilizedin this study, as set forth below, with the percentages being by weight.

Percent Linear sodium alkyl (C -C benzol sulfonate (NaLAS) (or othersubstituted surfactant) 20 Sodium silicate 5 Laurie myristic monoethanolamide (LMMEA) 2 Sodium carboxyl methal cellulose (CMC) 0.5 Builder(STPP; NTA; DSDGA; etc.)

Sodium sulfate (Na SO QS Sodium silicate having a ratio of $102 to NaaOof about 2.40Ibw1s found to have favorable toxicity characteristics.

TABLE IL-DETERGENGY TESTS Average soil removal 1 Water Water hardnesshardness Active surfactant, percent by weight Builder, percent by weight140 p.p.m. 350 p.p.m.

Ionic:

NaLAEl, 20% STPP, 40% 26. 5 20.6

NaLAS, 20% DSDGA, 10%-.. 26.0 22. 5

N aLAS, 20% (NTA)Na-3, 40% 24. 3 24. 5

N aLAS, 20% Triglycolic oxidate homologue, 40%.- 22.1 19. 4

NaLAS, 20% Tetraglycolic oxidate homologue, 40% 21. 7 21. 2

N aLAS, 20% Glycerine ethoxylated oxidate homologue, 40%- 21.6 18. 9

N aLAS, 20% Pentaerythritol ethoxylated oxidate homologue 9 40% 24. 120. 2

NaLAS, 20% DSD GA, 20%; STPP 20% 22. 9 23. 6

NaLAS, 20% DSDGA, 20%; (NTAJNa; 20% 25. 9 23. 5

NaLAS, 20% DSD GA, 20%; (EDTA)N 4, 25.2 22. 8

NaLAS, 20%. DSD GA, 20%; NazCOz, 20%. 23. 6 20. 8

NaLAS, 20% DSDGA, 20%; NaQHCOz, 207 22.6 22. 2

TMS, 10% 19.7 17. 7

TMS, 20%. GA 20.9 20. 4

NaLAS, 10 25. 5 21. 9

NaaSTA, 13 25. 7 17. 7

NaLAS, 20%---. 30 25. 7 24. 1

NaLAS, 0% DGA, 20% 23. 7 23.8

Amphoteric: D GA, 40% 18. 4 20. 1

1 Soil removal percent=(A-B)/(C-B) X100 where A=reiiectance of swatchafter washing; B=reflectance of swatch before washing; and G=reflectenceof swatch before soiling. These results comprise averages from threetest fabrics: (at) commercial test fabrics; (b) commercial U.S. Testingfabrics; and (c) private laboratory prepared fabrics (carbon black, oilysoil, powder-dry application) 2 Linear sodium alkyl (Cm-C 4) benzolsulfonate.

3 Sodium tripolyphosphate.

4 Disodium diglycolic acid.

I N itrilotriaeetic trisodium salt.

0 1,2 Bis (carboxy-methoxy-ethane) disodium salt.

7 1,2 Bis(carboxy-methoxy-ethyl other) disodium salt.

8 Tris(carboxymethoxy-ethoxy) propane trisodium salt.

2 Symmetrical tetra(carboxy-methoxy)-neopentane tetrasodium salt.

Ethylene diamine tetraacetic acid tetrasodium salt.

11 Sodium alpha-sulfo-tallow methyl ester.

11 tallow, 20% coconut soap.

Sodium tallow alcohol sulfate.

14 Disodium alpha-suliotallow acid.

16 Trade name of General Mills for an amphoterie surfactant (N -laurylmyristyl beta-amino propronic acid).

As shown, the builders of the invention compared very favorably withknown builders and are, in certain instances advantageously combinablewith such known builders and detergent components or adjuvants indetergent compositions for improved soil removal. It will be noted fromTable II that the builders of the'instant invention can be formulatedwith a wide range of organic surfactants as well as soap combinations;and that the resulting detergent formulations exhibit detergencycharacteristics compared to present-day detergents.

To yet additionally illustrate the builders ofthe invention and comparethem with known builders, additional detergent formulations wereproduced which were nonionic and identical to each other except for thebuilder and the level of builder in the formulations. Again,standardized aqueous solutions were studiedhaving a hardness of 180 ppm,a temperature of 120 F.,- a total detergent concentration of about 0.15%and again Standard Terg-o-Tometer laboratory detergency tests wereconducted using standard soiled cloths.

Those tests were conducted using the following exemplary embodiments ofa nonionic detergent formulation; with the percentages being by weight:

Percent Tergitol 15-S9 1 (a nonionic surfactant) 10 Sodium carboxymethyl cellulose (CMC) 0.5 Sodium silicate 5.0

Builder (STP P; DSDGA; etc.) 20-50 Sodium sulfate (Na SO QS A trade nameof Union Carbide for a linear cia-i'r alcohol etlgtiigyliated with 9mols ethylene oxide.

TABLE IIL-DETERGENOY TESTS Detergency units (NTA)NE3, 20% (NTA)Naa, 30,(NTA)Nfla, 40', (NTA)Na 50 :osn (3A1 40%.. DSD GA, 50%

DKD GA, 20 1-. DKD GA, 30%

DKD GA, 40".. DKD GA, 50

SKD GA, 40 SKD The data in Table III shows that the builders of theinstant invention also compared favorably with known builders, andappear to have some additional advantage at lower concentration levels,such as at 20% builder utilized in Terg-o-Torneter tests 'in which thesolid is added and suspended in the detergent test solution (0.10%)afterwhich clean fabricswatches are immersed for twenty minutes, 90cycles per minute agitation, at

120 F. liquor temperature. The wash cycle is fol- Percent Linear sodiumalkyl (C -C14) benzol sulfonate 10 NaLAS active) (or other substitutedsurfactant) 20 Sodium carboxy methyl cellulose (CMC) 0.5 Sodium silicate5.0 Builder (STPP; NTA; DSDGA; etc.) 40

Sodium sulfate (Na SOQ Q3 1 1 Quantity sulficient. 14 See Footnote atend of Table II.

TABLE IV.REDEPOSITION TESTS Redeposition Index 1 Indian head Terry clothBuilder cotton cotton No builder 85. 5 74. 9 90. 1 81. 5 87. 7 79.5 88.7 81. 6

3O RarXlOO Redeposition Index: R where Rsr swatch reflectance afterwashing; Rai=swatch reflectance before washing.

The above results show that the DSDGA builder embodiment of the instantinvention demonstrates comparable anti-redeposition properties to theother known builders tested in the described detergent formulations.

Similar redeposition tests were conducted on the nonionic baseddetergent formulation. previously described (see Table III). Theexperimental results are set forth in Table V.

TABLE V.REDEPOSIT1ION TES TS' Redeposltion Index Indian head Terry clothBuilder cotton cotton 1 See footnote at end of Table IV.

The above results again demonstrate that the preferred builder of theinstant invention compares closely with the other known builders andexhibits good anti-redeposition properties for the formulations tested.

Most of the foregoing detergent formulations represented typicalsolid-type product forms; namely, flakes, beads, tablets, powders,pellets, etc. While in general these formulations can be dissolved invarious aqueous and aqueous-solvent systems, such as ethanol and watermixtures, in order to obtain higher liquid concentrates, suchformulations will generally be made with little or no inorganic saltfiller .(such as added sodium sulfate, or sodium chloride), and may usehydrotropic agents and/ or co-solvent systems.

The following is an exemplary embodiment of a heavyduty liquid detergentconcentrate prepared with a selected 1 1 builder salt of the instantinvention; with the percentages being by weight.

, Percent Bio-Soft EA-lO (LAEO) [a trade name of Stepan Chemical Companyfor a nonionic 100% active surfactant, a linear alcohol alkoxylateethoxylated Water (H O) QS. Potassium hydroxide (KOH), Q8 1 to pH 10.

1 Quantity suflicient.

A clear, stable, liquid floor cleaner formulation was prepared asfollows:

Percent Ninol 1285 [a trade name of Stepan Chemical Company for acoconut diethanolamide] Builder (DKTGA) 10 Sodium xylane sulfonate 0.5Water (H O) 82.5

The builders of the invention were studied for toxicity and irritancy inaccordance with standard procedures to determined the acuate oraltoxicity, primary skin irritation and eye irritation potential thereofand compare such properties against at least certain known builders indetergent formulations.

TOXICITYIIRRITANOY RESULTS Irritancy test, 1% LDM active Draze LDio, 100abraded and rabbit Material as 15 basis unabraded eye Heavy dutyform-DSD GA 1 3. 7 Heavy duty form-STPP 1 6. 2

s l 20% NaLAS; 20% DSD GA; 5% Na; 0.5% Na-CMC and 54.5% NazSO Same asabove, except 20% STPP used in place ofDSDGA.

An interesting fact of the above study is that the higher homologue,i.e., triglycolic acid compound, is substantially less toxic thandiglycolic. The decrease in toxicity by the addition of one mol ofethylene oxide is unexpected. It is presumed that still further additionof ethylene oxide, i.e. higher homologues of diglycolic, are even lesstoxic, for example, see Gleason et al., Clinical Toxicology ofCommercial Products, 3rd Ed. (Williams & Wilkins, Baltimore, Md.) 1969.

The biodegradability of the builders of the invention was studied by afive-day biological oxygen demand test. Using a Madision, Wis. sewageplant seed more oxygen was consumed when one of the builders (DSDGA) wasincorporated, than when it was absent, and this indicates that thebuilder can be metabolized by normal, activated sludge. It is expectedthat other builders of the invention are also biodegradable, forexample, see Chemical Abstracts, 1971, 99.399n.

The builders of the invention are compatible with and easily formulatedinto various light and heavy-duty detergent formulations, dishwashingformulations, institutional cleansing formulations, metal cleansingformulations, etc., and are relatively stable in either liquid or dryform over extended periods of time at ambient conditions. The buildersof the invention may exhibit some hydroscopic properties somewhatsimilar to the known builders, and, in certain instances it isadvantageous to incorporate various anti-tacking agents and the likeinto detergent formulations utilizing the builders of the invention.Anti-tacking or anti-caking agents are utilized in a wide range ofamounts, ranging from about 1% to 30% by weight of the detergentcomposition. Such anti-tacking additives include alkali metal salts ofoxalic, maleic, fumaric, thiodisuccinic and sulfonoacetic acids;specially formulated caustic soda; combinations of nonsoap syntheticanionic or nonionic surfactants; alkali metal salts of toluenesulfonatein combination with polyvinyl chloride resins or polychloride-butadienecopolymer resins; combinations of NH 'H P0 and (NH HPO dialkali metalsalts of benzene-disulfonate or toluenedisulfonate; alkali metal saltsof sulfosuccinate; silicones, chlorosilanes, alkoxysilanes,polysiloxanes, alkali metal salts of alkylnaphthalenesulfonates,ethylene glycolethylene oxide condensation products having molecularweights of about 1500 to 2500; addition products of ethylene oxide andoleyl alcohol, Na P O alkali metal salts of sulfosuccinates,xylenesulfonate or tripolyphosphate; Cab-O-Sil (a registered trademarkfor a pyrogenic silica), Santocel (a registered trademark for a silicaaerogel), alkali metal salts of carbonic acid and alkali metal salts ofortho-, iso or terephthalic acid, etc.

The foregoing illustrations and examples set forth the characteristicsof certain specific builders of the invention and it will be appreciatedthat other builders of the invention yield similar results.

Additives which can be used with the instant detergent builders includetarnish inhibitors (such as benzotriazole, ethylene thiourea, etc.,perfumes, coloring agents, optical brighteners, corrosion inhibitors(such as silicates, etc.), hydrotopes (such as benzene, toluene, xylene,cumene, etc., and their sulfonate salts), alkalies (such as causticcarbonate, bicarbonate, etc.), bleaching agents (such astrichlorocarbanilide, etc.), and foam boosters (such as coconutethanolamides, etc.), and salts (such as Na 'SO- NaCl, MgSO etc.).

The builders of the invention are readily incorporated into varioustypes of detergent formulations, i.e. freefiowing powders, beads,flakes, pellets, etc. by conventional techniques and finished to aselected form, for example, see I. C. Ingram Outline of Processes Usedin the Drying of Soaps and Detergents, the Journal of the American OilChemists Society, vol. 33, November 1956, pp. 579-585.

Various changa and modifications to the above described embodiments ofthe invention may be made without departing from the spirit and scopethereof and it is intended that all matters contained in the abovedescription shall be interpreted as illustrative and not as limiting.

We claim as our invention:

1. A washing composition consisting essentially of a synthetic organicdetergent selected from the group consisting of non-soap anionics,soaps, nonionics, and amphoteric surface active compounds, and a buildermaterial selected from the group consisting of alkali metal, NH; andamine salts of 1,2-bis(carboxy-methoxy-ethane) acid, 1,2bis(carboxy-methoxy-ethyl-ether) acid, tris- (carboxy-methoxy-ethoxy)propane, symmetrical tetra- (carboxy-methoxy) neo-pentane and mixturesthereof, said builder and said organic detergent being present in saidwashing composition in a weight ratio ranging from about 20:1 to about1:10.

2. A washing composition as defined in claim 1 wherein the organicdetergent is a non-soap anionic surface active compound.

3. -A washing composition as defined in claim 1 which includes asupplemental builder selected from the group consisting of alkali metalpolyphosphates, aminopolycarboxylates and mixtures thereof, saidaliphatic oxy-hydrocarbon carboxylic compound and said additionalbuilder 13 being present in said washing composition in a weight ratioranging from about 1:10 to about :1.

4. A washing composition as defined in claim 1 wherein the builder is awater-soluble salt of 1,2-bis(carboxymethoxy-ethane) acid.

5. A washing composition as defined in claim 1 wherein the builder is awater-soluble salt of l,2-bis(carboxymethoxy-ethyl-ether) acid.

6. A washing composition as defined in claim 1 wherein the builder is awater-soluble salt of tris(carboxy-methoxy-ethoxy) propane.

7. A washing composition as defined in claim 1 wherein the builder is awater-soluble salt of symmetrical tetra- (carboxy-methoxy) neo-pentane.

8. A washing composition as defined in claim 1 wherein the builder is1,2-bis(carboxy-methoxy-ethane) disodium salt.

9. A washing composition as defined in claim 1 wherein the builder is1,2-bis(carboxy-methoxy-ethyl-ether) disodium salt.

10. A Washing composition as defined in claim 1 wherein the builder istris(carboxy-methoxy-ethoxy) propane trisodium salt.

11. A washing composition as defined in claim 1 wherein the builder issymmetrical tetra(carboxy-methoxy) neo-pentane tetrasodium salt.

12. A washing composition as defined in claim 1 including about 1 to 30%by weight of an anti-caking agent.

14 References Cited UNITED STATES PATENTS 3,661,787 5/1972 Brown 252-1093,635,830 1/ 1972 Lamberti et a1 25289 X 3,580,852 5/1971 Yang 252-3,459,670 8/ 1969 Carter 25 2-99 3,368,978 2/1968 Irani 252527 3,293,17612/196-6 White 210-58 2,817,606 12/ 1957 Barrett 252-144 X 2,311,008 2/l 943 Tucker 21023 2,264,103 11/1941 Tucker 210-23 FOREIGN PATENTS853,647 10/1970 Canada 252-132 639,491 6/1950 Great Britain 260535 OTHERREFERENCES Amino Acid Chelating Agents in Detergent Applications by R.R. Pollard, Soap & Chemical Specialties, September 1966, pp. 58-62 and130435.

LEON D. ROSDOL, Primary Examiner D L. ALBRECHT, Assistant Examiner U.S.Cl. X.R.

260-537 R; 25289, 132, 135, 180, 526, DIGEST 11

